Stretching as part of an exercise program is widely accepted by health professionals, physical trainers, and coaches, as a way to prepare for physical activity and to gain range of motion lost due to inactivity, disease, aging, unbalanced training, and so on. Regular stretching of the body muscles increases or maintains both the flexibility and range of motion of the joints. This can result in both the muscles and associated structures being more able to withstand sudden movements and more biomechanically correct movement patterns being permitted, which, by themselves, can significantly reduce the occurrence of injury. One example of this last point is in the case of lower back injuries, which often result from poor lifting technique. However, poor lifting technique is often the result of the individual being too inflexible to squat down sufficiently low. Such an individual must round the back to lift things, which is a widely acknowledged position of risk for incurring lower back injuries.
To help remedy this situation, the muscles must be stretched properly to avoid injury during the stretching exercise itself. Application of too much force too fast can cause injury; it is preferable to approach the range-of-motion limit gradually and apply just enough force to accurately position the body segment to be stretched. Moreover, the ideal way to stretch muscles is while the muscles are in a relaxed state, thereby maximizing the range of motion of the joint while minimizing the likelihood of a muscle pull or other injury.
However, it is difficult for an individual to apply a gradual, static stretch to muscles, especially the larger muscles of the legs, for example, the hamstring muscles. One common manner of stretching the hamstring muscles is to lie in a supine position with the leg to be stretched raised up in the air and the other leg on the floor. Then, either the exerciser, him- or herself, pulls the raised leg forwardly toward his or her head by grasping the back of the thigh with the hands, or a second individual pushes against the raised leg. As can be appreciated, it is difficult for either the exerciser or the assistant to accurately position and then hold the leg. Either the exerciser cannot relax due to the effort required to stabilize the leg and actuate the stretch, or the stability and actuation efforts provided by the partner, which permit the exerciser to relax, cannot provide the exact positioning required for an efficient stretch, since the assistant cannot know what the exerciser is feeling. A convenient, safe, and affordable aid to performing this maneuver can help inflexible individuals gain or maintain flexibility to help prevent injuries.
Various tubular frame apparatus have been developed for performing strength-building floor exercises, that is, exercises performed while moving about a floor with the apparatus providing assistance. Since stretching is traditionally performed on a floor, it is often erroneously included in this group of strength building exercises. However, stretching is a distinctly different activity since the limit of position of the body segment is the determining factor, not the load or cumulative work, as is the case with strength-building exercises. Therefore, apparatus designed for strengthening alone seldom possess the features needed to address the determining factors in stretching, namely, allowing for body segment relaxation, a low strength requirement during use, and leverage to allow easily achieved positioning. One such type of strengthening apparatus utilizes a tubular frame with one or more crosspiece elements, where various body segments can be positioned and the motion thereof resisted by other body segments. Examples of this type of apparatus are disclosed by U.S. Pat. Nos. 3,540,724 and 3,920,240. This type of apparatus has the inherent disadvantage of not allowing a mechanical advantage of the kind to apply leveraged, gradually applicable forces to body segments stabilized by the apparatus itself. Because of this, such apparatus do not permit the kind of relaxation desired for proper stretching. The degree of athleticism required to operate such apparatus, due to their lack of the aforementioned features, limits their use to only already physically fit individuals.
In another class of apparatus, bent metal tubing is used to create a frame for the exercising of leg muscles. Examples of this type of apparatus are disclosed by U.S. Pat. Nos. 2,644,688 and 5,236,333. Drawbacks of these particular kinds of apparatus include the requirement that the user be seated in a chair to operate them, and that they are limited in their application to exercising certain leg muscle groups only.
Prior to the present invention, the inventor has been awarded U.S. Pat. No. 5,122,106 for a stretching apparatus. While well suited to its intended purpose, it has certain limitations in the mass consumer and medical markets due to complexity and cost of construction, floor space and volume required for storage, and specialty of function.